Security-Aware Scheduling for TTEthernet-Based Real-Time Automotive Systems

Abstract

TTEthernet is a deterministic, congestion-free, and high-bandwidth communication protocol based on the Ethernet standard that provides a powerful network solution for developing safety-critical distributed real-time automotive systems. With the development of intelligence and networking of vehicles, such systems are becoming increasingly connected to external environments; thus, security has become a pressing issue in system design. However, TTEthernet-based architecture does not have direct support for secure communication. When deploying the security mechanisms on these architectures, a major challenge is to guarantee the schedulability of systems, given the tight resource constraints and strict timing constraints. In this paper, we apply an authentication mechanism based on the delayed exposure of one-way key chains to protect the authenticity of messages on TTEthernet and make a slight modification to reduce the authentication delay. On that basis, we propose a mixed integer linear programming formulation for solving the scheduling problem of the TTEthernet-based real-time automotive systems subject to both authentication mechanism constraints and other traditional design constraints. The extensive experiments are conducted to demonstrate the effectiveness and efficiency of the proposed method.INDEX TERMS TTEthernet, real-time, automotive systems, security, scheduling.

Dependability-Aware Routing and Scheduling for Time-Sensitive Networking

“…Each key is assigned to one interval. The protocol is bootstrapped by creating this chain and securely distributing K 0 to all receivers [47].…”

“…Due to the deterministic nature of our schedule, we can make some modifications to the basic TESLA protocol without sacrificing security. The first modification is adopted from [47]. Since bandwidth is scarce, we do not release the key K i−d with every message/stream.…”

“…This section presents the architecture and application models, as well as the threat, security and fault models. Our application model is similar to the one used in related work [47], but we have extended it to consider TSN networks and the optimization of redundant routing in conjunction with scheduling.…”

“…Therefore, the security aspects should be equally important to the safety aspects. Timed Efficient Stream Loss-Tolerant Authentication (TESLA) [30] has been investigated as a low resource authentication protocol for several networks, such as FlexRay and TTEthernet [47] networks. Adding security mechanisms such as TESLA after the scheduling stage is oftentimes not possible without breaking real-time constraints, e.g.…”

“…Adding security mechanisms such as TESLA after the scheduling stage is oftentimes not possible without breaking real-time constraints, e.g. on end-to-end latency, and degrading the performance of the system [47]. Thus we consider TESLA and the overhead and constraints it imposes part of our configuration synthesis problem formulation.…”